Differential flow device with valve controlling means



July '7, 1942.

A. BoYNToN DIFFERENTIAL FLOW DEVICE WITH VALVE CONTROLLING MEANS FiledDeo. 8, 1959 fig. 1.

3- Sheets-Sheet, l

ALEXANDER BOYNTON,

Fig.2.

ATTORNEYS.

July 7, 1942. y A, BOYNTON 2,288,605

DIFFERENTIAL FLOW DEVICE WITH VALVE GOTROLLING MEANS ATTORNEYS.

July 711942- A. BoYNToN 2,288,605

DIFFERENTIAL FLOW DEVICE WTH VALVE CONTROLLING MEANS Filed Dec. 8', 19393 Sheets-Sheet 3 M n l" no 10s losa-1: ||7

g1 |00 OOC |000 |02l 99a 9E 98 l L 9e L ALEXANDER BOYNTON, e1 1NVENT0R,76 m L A BY Lw f m7600017) FigJZ.

ATTORNEYS.

Patented July 7, 1942 UNITED STATES PATENT OFFICE DIFFERENTIAL FLOWDEVICE WITH VALVE CONTROLLING MEANS Alexander Boynton, San Antonio, Tex.

Application December 8, 1939, Serial No. 308,316

16 Claims.

Another object is to provide a means for holding the valve seatedindependently of the differential force.

Another object is to cause the differential valve seating force to actupon an area larger than that of the valve.

In accomplishing these and other objects, I employ a piston ofrelatively large diameter to operate a spring-loaded valvelof lessdiameter in combination with a lubricated latch and a check valve, aswill be clearly understood from the following specication andaccompanying drawings in which- Fig. l is a longitudinall sectionthrough the preferred embodiment fovr tubing flow.

Fig. 2 is a longitudinal section through a modified form for tubing ow,showing the valve open and the latch disengaged.

Fig. 3 is a longitudinal section through a portion of a modification ofthe construction shown in Fig. 1.

Fig. 4 isa longitudinal section of a portion of the device illustratedin Fig. 2, showing the valve closed and the latch mengaged.

Fig. 5 is a longitudinal section through a modied form of the inventionadapted .for either tubing or casing flow.

Fig. 6 is a cross section on the line 66, Fig. l.

Fig. l is a cross section on the line 'I--1, Fig. 1.

Fig. 8 is a cross section on the line 8--8, Fig. 2.

Fig. 9 is a cross section on the line 9 9, Fig. 4.

Fig. 10 is a cross section on the line Ill-I0, Fig. 5.

Fig. 11 is a longitudinal section of another modied form adapted foreither tubing or casing flow. Y

Fig. 12 is a partial installation plan showing the upper end of a wellwith a flow intermitter.

Fig. 13, showing the devices installed in a well, extends downward fromthe showing in Fig. 12, and completes the installation plan.

Similar characters of reference are employed to designate similar partsthroughout the several views.

The column of well liquid caused to stand up in the eduction tube inbalance against the pressure uid, whether in the tubing or in the casing(depending upon the path of ow) will be referred to as the upstandingcolumn.

The diiference between the force of the pressure fluid and the forceexerted by the upstanding column will be referred to as thedifferential.

The valve controlling the admission of pressure fluid into theupstanding column will be designated as the pressure fluid valve.

The parts 4 to 8, both inclusive, will be referred to as the movablepiston assembly.

Three forces are manifested in the operation of this device. Thepressure fluid exerts one constant force, and the spring exerts theother# while the pressure of the upstanding column is the only variableforce.

Referring to Fig. 1, showing a device for tubing now, the nipple I,adapted to be threadedly connected into the well tubing, has a lateralshell 2 which may be cast integrally with it. This shell, having theupper guide slope 2f and the lower guide slope 2g, has its upper endhermetically closed by the plug 3 and its lower end hermetically closedby the plug 3. The member 8 may be pressed into the chamber 2c andlanded upon the shoulder 2a.

The piston base 5, having the central opening 4b and the cross bores 5b,has an external annular shoulder upon which the U cup 6 is secured bytheV ring l. This ring has threaded engagement over the upper extremityof the member 5 where it may be locked in position to properly engagethe U cup by the valve member 4, likewise having threaded engagementwith the upper extremity of the member 5.

The latch rod 9, having threaded engagement within the lower extremityof the member 5, has a winged nut I I threadedly engaged over its lowerextremity and locked by the nut I2. The coiled spring I3, having slightclearance within the chamber 2c and over the member IB, is `installedunder some compression between the Wings Ila of the nut II, having endclearance within the chamber 2c, and an external annular flangel at theupper extremity of the member I6.

The latch roof member I5, having its upper end landed centrally underthe member 8, has its inclined ball roof I5a engaged upon the latchballs I4 supported upon the ball floor Ilia. The ball roof and oorconstantly urge the latch balls inwardly by the expansive force of thespring I3. This spring also causes the valve 5a normally to engageyieldably upon the seat 8a, While the valve 4a is also normally somewhatwithin the lower portion of the metering chamber 3b.

When the movable piston assembly is urged upwardly by sufilcientdifferential. the valve 4b will land upon the seat 3a and the latchballs will engage within the annular recess 9a (see Fig. 3).

It will be noted that there is some clearance between the upper end ofthe member I6 and f the member 8, in order that the *ull force of thespring I3 constantly will urge the downwardly inclined latch floor I6atoward the upwardly inclined latch roof Ia, which inclined surfacesconstantly tend to force the latch balls inwardly.

When the valve la is engaged upon its seat 3a, the latch balls shouldengage upon the upper portion of the latching surface 9a, as appears inFig. 3, in order that the valve la will be firmly seated by the latchforce while the latch is engaged. The rod 9 may be screwed inwardly oroutwardly within the member 8 to obtain such adjustment which may besecured by the lock plugIIl.

The chamber 2c may be filled with a viscous liquid such as castor oiland graphite or ground lead and oil. 'Ihe normal seating of the valve 5aupon its seat within the member 8 will prevent the liquid within thechamber 2c from leaking out before the devices are installed. The slightclearance 8d, between the rod 9 and the member 8, and the lateralopenings |5b and |6b of the members I5 and I6, respectively, enable therod 9 to be raised without tending to pull a vacuum within the chamber2c and to be lowered without becoming implnged upon the liquid withinthat chamber.

The path of the pressure fluid through the device is through theexternal lateral opening 2d; thence via the chamber 2h, the openings 8b,the lower metering chamber 8c, the cross bores 5b, the passage 4b, theupper metering chamber 3b, and out into the tubing through the lateralopening 2e. As the movable piston assembly rises, the U cup 6 will beexpanded against the polished wall of the chamber 2b by pressure fluidentering through the small slots 5d.

The central enlargement of the piston base 5, the U cup 6, and the ring1 have a close sliding ilt within the chamber 2b. The lower enlargedportion of the rod 9 is, likewise, closely slidable within the member I5and through the latch floor I6a.

During the upward movement of the movable valve assembly, it is evidentthat the lower extremity 5c of the member 5 will throttle the flow ofpressure fluid through the metering chamber 8c until the valve member 4assumes a similar function within the metering chamber 3b, thuscontrolling the flow of pressure fluid through the device in such manneras to permit the greatest flow thereof at any desired differential,depending upon the relative lengths of the two metering chambers which,of course, may be different. Increasing or decreasing the differentialat which the pressure fluid valve will close also will change the volumeof pressure fluid discharged through the device approximately inproportion to such increase or decrease in the valve closingdifferential.

The intake and discharge openings 2d and 2e should be much larger thanthe openings 4b and 5b through the movable piston assembly. This is sobecause the differential which actuates the pressure fluid valve iscreated by the comparatively restricted opening through the members 4and 5. The requirement for relatively large intake and dischargeopenings also applies to the constructions illustrated in Figs. 2, 5,and 11, but

will not be repeated in connection with the embodiments therein shown.

In Fig. 3, illustrating a modified form, also adapted for tubing flow, acheck valve is employed in combination with the latch shown in Fig. 1.The latch will hold the valve 4a (not shown, but the same as in Fig. l)seated against a predetermined differential. When the latch releases,the check valve will cause the pressure fluid valve 4a to open slowly byimpeding the movement of the viscous liquid within the chamber 2c; andherein resides one of the most important features of this invention.

The valve seat member I1, having its upper portion formed the same asthe member 8 in Fig. 1, may be pressed into the shell 2 and landed uponthe small internal shoulder 2a. The lower portion has the openings Ilaand |1b to allow for free movement of the viscous liquid into and out ofthe chamber 2c as the rod 9 moves upward and downward. The lower end ofthe member I1 has the inclined surface I1c co-acting with the inclinedsurface Ia of the member I8, slidable within the chamber 2c. Theseinclined surfaces urge the latch balls I4 against the rod 9, having thelatching surface 9a (Fig. 1) within which the balls engage when thevalve 4a is closed upon its seat 3a, as was explained for Fig. 1.

'I'he lower end of the shaft 9 has threaded engagement with the checkvalve base I9, having the longitudinal peripheral slots |9a, theperipheral recess |9b, the lateral openings I9c, the longitudinalopenings |9d, and the depending shank |9e. Over this shank the coiledspring 2 0 is installed under slight compression between the check valve2| and the nuts 22, and normally urges the valve 2| to seat resilientlyupon the nether side of the member I9, slidable within the chamber 2c.

The valve 2| has a depending tubular shell 2|a, having the lateralopenings 2lb for circulation of fluid as the check valve opens andcloses. This shell is slidable over the nuts 22 which guide it truly toseat the valve.

The pressure fluid valve may close quickly upon its seat 3a because thecheck valve 2| will open to allow free fluid passage through theopenings I9d as the base I9 is raised. l The pressure fluid valve willopen slowly afterthe latch springs, because the check valve 2| willremain closed then; thereby forcing-.the liquid under the member I9through the small slots IQa.

Parts shown in Fig. 3 which bear the same reference characters as thesimilar parts in Fig. 1 will be understood to be similar in constructionand purpose to those there shown.

In Fig. 2, illustrating another modification of the invention for tubingflow, the plunger '26 has a central portion of enlarged diameter 26aclosely slidable within the chamber 23d. 'I'his enlargement has thesmall longitudinal peripheral slots 26d through which the pressure fluidflows. The member 26 has its lower end formed into the valve 26e adaptedto close upon the seat 23h, and having slight clearance within the lowerend of the upwardly flared metering chamber 23e. The head 26h has slightclearance within the upper portion of the downwardly flared meteringchamber 24b and is positioned normally proximate the upper end of thechamber 24h; while the valve 26e is slightly Within the chamber 23e. Thechamber 23d is of such length that the enlargement 26a will stop somedistance above the upper end of the chamber 23o when the valve 28eengages its seat 2lb. The threaded opening 28e is for a testing toolemployed to adjust the setting of the latch inassembling.

The rod 21, having comparatively large clearance within the opening231", has threaded connection with the plunger 28 and with the latch rod28. The lock nut 28h affords means for securing the latch adjustment bylocking the threaded engagement between the members 21 and 28. The latchmay be also adjusted by screwing the member 32 upward or downward.

'Ihe valve travel `spacer ring 31, having the openings 81a, may bepressed into the chamber 23g and landed upon the slight internal annularshoulder 23f. 'This ring has a central opening through which the rod 28`is freely slidable. The valve member 38, having large clearance withinthe chamber 23g, has its upper outer surface formed into a valve adaptedto engage the seat 31h of the member 31. The central opening through themember 38 has an internal annular ange engageable with the upperenlarged portion of the rod 28, by which engagement the spring 23,having slight clearance within the chamber 23g, is compressed on thedownward stroke of this rod, as appears in Fig. 4, which illustrates thevalve 26c of Fig. 2 seated and the latch engaged.

The latch base ring 32 has threaded engagement within the lower portionof the shell 23 and supports the ball lloor 3|, having an inclined uppersurface engaging the balls I4. The ball roof 30, having an inclinedlower surface engaging the latch balls, is urged downward by the coiledspring 23, installed under some compression in Fig. 2, and compressibleas shown in Fig. 4. The inclined surfaces of the members 30 and 3| areadapted to urge the latch balls inwardly to contact the rod 28. When theplunger 26 is in its normal position unmoved by the differential, thelatch is disengaged, as in Fig. 2. When the pressure iluid valve 26e isseated, the latch balls are engaged upon the latching surface 28a, as inFig. 4.

The intake bushing 24, having the intake opening 24a and the meteringchamber 24o, is threadedly engaged within the upper end of the shell 23and landed upon the internal annular shoulder 23h.

The chamber 23g has its lower end hermetically closed by the plug 25engaging the gland ring 35, which has slight clearance within the shell23, upon the packing 34. The gland base 33,

also having slight clearance within the shell 23, I

is engaged between the packing aiml the latch base ring 32.

The ring 36, supported by an annular shoulder within the plug 25, hasslight clearance within the plug and over the lower portion of the rod28. This ring acts as a brake to cause the valve 26o to move slowly awayfrom its seat 23h after the latch springs, but oiers no resistance tothe seating of this valve. This is true because on the downward strokeof the valve 26e the ring 36 will be floated freely upward by thedisplaced liquid below it within the plug 25 as vthe rod 28 movesdownward through it, as appears in Fig. 4. On the unseating stroke ofthe valve 26e, the ring 36 willbe drawn downward by the liquid above it,attempting to replace the displacement of the rod 28, as it iswithdrawn. The slight clearance between this ring and the rod causessuch replacement to be accomplished slowly. Thus a brake is provided toslow down iii) the opening movement of the pressure duid valve. Thisbrake action prevents the valve 28e from vibrating and fluttering afterthe latch springs.

The chamber 23g may be illled with a viscous liquid such as castor oiland graphite or ground lead and oil. The clearance between the valvemember 38 and the wall of the chamber 23g, the openings 31a, theperipheral slots 30a and 3Ia, the cross slots 32a, the annular recess32h, and the clearance of the members 30, 3l, and 32, with the rod 28,provide that the liquid within Athe chamber 23g may circulate responsiveto the movements of the rod 28.

The path of the presure fluid through the device is via the intakeopening 24a, the clearance around the plunger head 26, theperipheralslots 26d, the chambers 23d and 23e, the opening 237', the chamber 23e,and the lateral opening 23a, from which it enters the upstanding columnof well liquid in the tubing.

It will be observed in Fig. 2 that thehead 26h is positioned normallyproximate the upper end of the metering chamber 24h and that the lowerenlargement, having its lower end formed into the valve 28e, ispositioned normally proximate the upper end of the metering chamber 23o.The clearance around the head 2Gb will increase, and the clearancearound the lower enlargement will decrease as the valve 26e approachesits seat 23h. In this manner, the greatest volume of pressure iluid willbe discharged through the device at approximately one-half of thediferential required to seat the valve 26e. Ob viously, the differentialat whichV the device will allow the greatest volume of pressure uid topass through it may be varied by varying the relative lengths of the twometering chambers, as stated in connection with Fig. 1. Varying thedifferential at which the pressure fluid valve 26e will close will also,in a large degree, proportionately vary the volume of pressure fluidpassing through the device, as will be understood by those skilled inthe art.

It is apparent that the device illustrated in Fig. l for tubinglow canbe readily adapted for casing flow by closing the lateral openings 2eand 2d and providing the opening 27', opposite from the opening 2e, andthe opening 2k, opposite from the opening 2d.

The device shown in Fig. 2 for tubing llow also can be adapted forcasing flow by closing the openings 24a and 23a and providing in theirplace the openings 23k and 23m.

In Fig. 5, which illustrates the invention adapted to both tubing andcasing flow, the nipple I may be joined threadedly into the well tubing.This nipple has the lateral shell 39, hermetically closed at its upperend by'the plu-g 40, having formed within it the metering chamber 40h,and hermetically closed at its lower end by the plug 4I, having themetering chamber 4Ib formed within it. Preferably, both nipple and shellmay be cast integrally.

The valve tube 42 is slidable closely within the members 44 and 48 andis slidable loosely within the members 45 and 41. The spring compressionring 43, which may be pressed over and secured upon the tube 42 by thewelds 43a, has slight clearance within the chamber 39e.

The upper ball roof 44, having its nether side formed to the slopingsurface 44a, may be joined threadedly into the chamber 39e. The balliloor 45, having its upper side formed to the sloping surface 45a, isslidable within the chamber 39e. The latch balls 46 are urged inwardlyby the sloping surfaces 44a and 45a, co-acting with the expansive forceof the coiled spring 52, installed under some compression between themembers 43 and 45.

The lower ball floor 48, having its upper side formed to the slopingsurface 48a, may be threadedly secured within the upper end of thechamber 39d. The lower ball roof 4l, having its lower side formed to thesloping surface 41a, has clearance within the chamber 39e and is engagedupon the lower latch balls 49 by the force of the coiled spring 53,installed under some compression between the members 43 and 41. Thesloping surfaces 41a and 48a urge the latch balls inwardly against thetube 42 by force of the spring 53.

The upper latching surface 42e is adapted to be engaged by the upperlatch balls 46 when the upper valve 42a is closed upon the seat 40a. Thelower latching surface 42f is adapted to be engaged by the lower latchballs 49 when the valve 42e is closed upon the seat 4IG. The valves 42aand 42c will engage their respective seats at a predetermineddifferential and the latches will release the tube 42 at a'pre-determined lesser differential, or th latches may be adjusted torelease at different differentials by varying the depth of engagement ofthe latch balls with the surfaces 42e and 421. This depth of engagementmay be adjusted by screwing the members 44 and 48 upwardly ordownwardly, as is apparent.

The chamber 39e may be filled with a viscous lubricant to lubricate thelatch and to slow down the valve travel when the latch springs. Theopenings 43h will be small if slow valve movement be desired, or theseopenings will be large if fast valve travel be preferred. This is true,because liquid within the chamber 39e must move through these openingswhen the tube 42 is actuated in either direction.

The metering chamber sleeve 59 may beV pressed into the shell 39 andlanded upon the small internal annular shoulder 39j. The meteringchamber 40b and 40e may be of the same or different lengths and of thesame or different diameters. The straight portion 40d preferably shouldhave the same length as the straight portion of the 'head 42h.

The metering chamber sleeve 5I may be pressed into the shell 39 andlanded upon the small internal annular shoulder 39g. The meteringchambers 4|b and 4|C may be of the same or different lengths anddiameters, as was stated for the upper metering chambers. One pair ofmetering chambers, also, may differ from the other pair in dimensions.The straight portion of the head 42d should be approximately of the samelength as that of the straight portion 4Id.

The head 42h should be positioned normally within the upper end of themetering chamber 49e with which it has some clearance, and the head 42dshould be positioned normally within the upper end of the meteringchamber 4 lc, with which it has some clearance, as appears in Fig. 5.

'I'he head 42h will have increasing clearance within the chamber 40c anddecreasing clearance within the chamber 40h as the valve 42a approachesits seat 40a. The head 42d will have increasing clearance within thechamber 4Ic and decreasing clearance within the chamber 41b as the valve42e approaches its seat 4la.

In this manner, the greatest volume of pressure fluid will pass throughthe device at a differential which may be approximately one-half of thedifferential required to seat either valve 42a or 42e.

In this construction, it will be understood that the differential actsupon either extremity of the tube 42 protruding outwardly of the membersy 44 and 48.

For tubing flow, the path of the pressure fluid will be into the shell39 through the lateral openings 39a and thence via the chamber 39C. themetering chambers 40C and 40h, the passage 42g, the metering chambers4lc and 4Ib,and into the tubing through the lateral opening 39h.

For casing flow, the pressure fluid will take the same path through thedevice as that above stated for the tubing flowl except the directionwill be reversed.

The upper metering chambers 49h and 40e ordinarily should have somewhatgreater clearance with the head 42D than the lower metering chambershave with the head 42d. This is true because the upper head 42h and thechambers 40h and 40e control the ow of pressure fluid into the annularspace between the tubing and the casing for casing flow; whereas, theyhead 42d. and the lower chambers 4Ib and 4Ic control the pressure fluidflow into the tubing for tubing ow.

Fig. ll illustrates a further modified form of the invention for bothtubing and casing flow.

The lateral shell 54 may be cast integrally with the nipple portion I.The upper end of this shell is closed hermetically by the plug 55engaging the gland ring 56 upon the packing 5l supported by the upperend of the sleeve 59 which may be pressed into the shell and landed uponthe small internal annular shoulder 54a. The interior of the member 58is formed into the central metering chamber 59a, the passage 59h, andthe chamber 58f.

The plunger 59 is engaged threadedly upon the rod 60 and locked by thelocking screw 6I in such position as to cause its valve 59e to engagethe seat 59C when the latch balls 69 engage upon the lower latchingsurface 62h, and to cause the valve 59h to engage the seat 54d when thelatch balls are engaged upon the upper latching surface 62a.

The central enlargement 59a of the plunger 59 is slidable closely withinthe chamber 54h and has the peripheral slots 59d to allow pressure fluidto pass.

The latch shaft 62 may be joined threadedly to the rod G0 and securedupon it by the weld 62d. The piston 65 may be pressed over the rod 69and secured to it by the weld 55a.

The diaphragm 6l. which may be of rubber, is engaged between theinternal annular shoulder 54j and the circular plate 66 by force of theupper coiled spring 63 installed under some compression between theplate 66 and the piston 65, this latter member being slidable freelywithin lthe chamber 547',

The ball roof 68, having the inclined surface 68a, is engaged upon thelatch balls 69 by the force of the lower coiled spring 64 installedunder some compression between the members 65 and 68. The ball oor 10,having the inclined surface 10a, rests upon the latch base ring 1I.

The inclined surfaces 68a and 10a urge the latch balls inwardly tocontact the shaft 62 by the force of the spring 64.

If the latch is to hold with equal force in both directions of the valvetravel, the latch should be adjusted so that the balls will engage moredeeply upon the surface 6217 than upon the surface 62a, because thespring is under greater compression when the valve 59h seats than whenthe valve 59c is seated.

'I'he lower end of the shell 54 is closed hermetically by the plug 14engaging upon the gland ring 15, which in turn, compresses the packing13 upon the other gland ring 12.

The latch balls may be raised or lowered by screwing the ring 1| upwardor downward, and the plunger 59 may be vraised or lowered by means ofits threaded connection with the rod 60, thus providing for allnecessary adjustments of the latch. The attened end 62e of the shaft 62and the wrench slots 59e upon the plunger enlargement 59a are providedfor convenience in making latch adjustments. i v

The chamber 547' may be filled with a viscous lubricant if it be desiredto slow down the valve travel when the latch releases. The openings 65hmay be made large or small to regulate further the speed with which thevalves will travel. The clearance which the members 68, 10, and 1| havewith the shaft 62, and the clearance which the members 68 and `10 havewithin the chamber 547' provide for free circulation of fluid as theshaft 62 moves upward or downward. The slots b and the annular recess10c are provided also for this purpose and enable the fluid to passfreely between the annular opening exterior of the members 68 and 10 andthe annular opening between the shaft 62 and the ring 1|.

The diaphragm 61, having a close t over the rod 60, will flex downwardlyto compensate for the outgo of the rod 60 when the valve 59e movesupwardly, and will ex upwardly to compensate for the incoming portion ofthis rod when the valve 59h moves downwardly. The opening 66a..

is somewhat larger than the rod 60 in order that the diaphragm 61 may beflexed freely bythe lluid under it.

While flowing the well through the tubing, the pressure fluid will enterthe device through the lateral opening 54h and be discharged into thetubing through the lateral opening 54o via the intervening passage 54e,the metering chamber 64g, the plunger chamber 54h, the other meteringchamber 58a, the central passage 58h, the lateral openings 58e. and therecess 58d.

Either of the embodiments herein shown may be joined into the welltubing at intervals which may vary between 150 and 300 feet. But,however, spaced, the pressure fluid valve should be adjusted so that theper square inch differential force required to close this valve will beapproximately equal to twice the force per square inch exerted at thebase of a column of well liquid as high as adjacent devices are spacedapart. In

this manner, an upper device will be closing while the next one belowwill be opening, if the power graph developed by the valves and meteringchambers is substantially triangular with the `two volume legs thereofof approximately equal length, as they preferably should be,

The pressure fluid force employed to flow the well may be somewhat morethan two or three times the differential force required to close thepressure fluid valves, depending upon depth and other well conditions.

For tubing ow, it will be assumed that either of the devices shown isconnected at proper intervals into the tubing 11 in Fig. 13. The. casinghead 18 may be employed proximately above the ground surface 8l toaffect a hermetic seal between the casing 16 and the tubing 11 intowhich the flow devices 82 are joined.

The well fluid from the formation 88 enters the annular space 94 throughthe gun perforations 81. An anchor string of tubing 86 may extend fromthe intake nipple 64 to the bottom of the well 85.

The normal liquid level is assumed to be at 89; The casing iiow pipe 80is closed and the tubing 11 is open to a iiow tank.

If pressure fluid now be turned into the annular space 94 through thepipeline 19, to flow the well through the tubing, the well liquid wil1be depressed in the casing to a level indicated at 90 and the liquidwithin the tubing 11 will be caused to rise `in balance against thepressure fluid force to a level indicated at 9|. The device 82 next tothe base of the upstanding liquid column in the tubing will be open anddischarging pressure fluid into the tubing. The device next above willbe partially open. As the liquid level in the annular space 94 islowered, the lower devices will open as the upper devices close. e

If a packer 95 be installed between the tubing and the casing, the checkvalve 83` will prevent the pressure fluid from contacting the producingformation 88, at any time..

To flow the well through the casing, theA device shown in either Fig. 5or Fig. 11 may be installed as for tubing flow, the check valve 83 beingremoved from the tubing. To start the flowing operation, close the pipeline 19, open the ow line 80, and admit pressure fluid through thetubing 11. This will cause the liquid in the tubing to become depressedto the level indicated at 92, and to upstand in the casing to the levelat 93. The devices will function for casing flow in a manner so similarto the operation above described for tubing flow as to require nofurther explanation.

In Fig. l2, I show an intermitter similar to one of the embodiments inmy co-pending applica- The plate |0| is slidable over the upper nippleof the tubular bracket 96. The plate member |08 is secured upon thepiston |03 by the set screw H1, and has an arm which supports the valveoperating shell 99.

The valve |09 has an arm |09a adapted to open and close the valve byslight rotation. The cross pin is secured through this arm and has itsends engaged within opposite spiral slots of the shell H0. When thisshell is moved uil ward by the piston |03, due to pressure acting 'uponthe piston from within the well, the spiral slots of the shell,co-acting with the pin cause the valve I 09 to open, and to 'close whenthe piston again moves downward.

The mechanical counter ||6, actuated by the finger |08a of the platemember |08, will record the number of valve-opening movements.

When the pressure builds up in the casing or is built up to apre-determined value through admission of pressure fluid from the line19, the pressure fluid force acting through the tubular bracket 96, theopenings |00c, |00b, of the oil retainer cup |00, and the opening 99athrough a central depending boss of the shell 99, will contact the lowerend of the piston |03 by acting on the lubricant |00c which followsunder the piston and spring the lower latch deriving its force from thespring |06; thereby opening the valve |09 by moving upwardly the spiralsof the shell ||0 over the arm |09 and the pin III, as previouslyexplained.

On the upstroke of the piston, the upper latch I I2 engages by force ofthe spring I3.

The valve |09, being now open and the Well flowing through the tubing11, the pressure within the annular space 94 (see Fig. 13) between thetubing and the casing ordinarily will decrease after a. pre-determinedowing period, or when the liquid head has been discharged and pressurefluid reaches the tubing intake nipple 84. When the pressure iluidbecomes depleted to a pre-determined value, the spring 98 will springthe upper latch ||2. The valve |09 will be then closed and the pistonand other movable parts will return to the position shown in Fig. l2.

For casing iiow, the intermitter assembly illustrated in Fig. 12 may beinstalled upon the casing and operated by controlled pressure from apipe line.

It is understood that the details of construction and arrangement ofparts are subject to many obvious variations and minor changes withoutdeparting from the scope and purpose of my invention as stated in theobjects and as deilned by the appended claims.

'I'he invention claimed is:

l. A iiow valve comprising a body having a passageway with an inlet andan outlet, a valve assembly movable within said passageway, saidassembly including oppositely extending valve members, spaced opposedmetering chambers in the passageway into which said valve members areadapted to move vto produce progressive throttling action upon pressureiiuid passing through the passageway under a differential pressurebetween the interior and exterior of the valve body, a valve seatposteriorly within each of the chambers, and adapted to be engaged byone of the valve members to close the passageway, means resilientlyholding the valve assembly at a predetermined position within thepassageway, and means for releasably latching the assembly in positionwhen one of the valve members engages its co-operating valve seat.

2. A flow valve comprising a body having a passageway with an inlet andan outlet, a valve assembly movable within said passageway, saidassembly including oppositely extending valve members with an axial boretherethrough, spaced opposed metering chambers in the passageway adaptedto receive said valve members, each of said chambers comprising a borehaving oppositely converging inner surfaces whereby fluid, passingthrough the passageway, is throttled during passage through one of thechambers, and means intermediate the metering chambers for normallyholding the valve assembly with the valves in the entrances to thechambers.

3. A ilow valve comprising a body having a passageway with an inlet andan outlet adjacent the opposite ends thereof, a valve assembly movableaxially of the passageway, a metering chamber comprising an inwardlyopening bore in each end of the passageway, a tubular member extendingaxially of the passageway, a tubular valve on each end of said memberand adapted to enter one of said chambers, and resilient means normallyholding the valve assembly with the valves in the entrances to themetering chambers.

4. A iiow valve comprising a body having a passageway with an inlet andan outlet adjacent the opposite ends thereof, spaced walls in thepassageway between the inlet and outlet, said walls having alignedopenings therein, a metering chamber in each end of the passageway inalignment with said openings, a valve assembly movable axially of thepassageway, said assembly comprising a tubular member passing throughsaid openings and including oppositely extending valve members adaptedto enter said chambers, a piston surrounding said tubular member, and aliquid iilling the chamber intermediate said spaced walls, there being arestricted passage from one side of the piston to the other so that themovement of the valve assembly is damped.

5. A flow valve comprising a body having a passageway, a v alve assemblymovable within said passageway, opposed metering chambers in thepassageway on opposite sides of the assembly, each of said meteringchambers comprising an inwardly tapering bore having a valve seat at itsinner end, oppositely extending valve members on said assembly adaptedto enter either of said bores to throttle the passage of uidtherethrough and to engage the associated seat upon the creation of apredetermined differential pressure between the interior and exterior ofthe valve body. and means for releasably latching the assembly inposition when the passageway is closed.

6. A flow valve compromising a body having a. passageway with an inletand an outlet, a valve assembly movable in said passageway and includingoppositely extending valve members, opposed valve seats ln thepassageway adapted to be engaged by said valve members and close thepassageway, a latch rod attached to said assembly and extending throughone of said valve seats, a chamber into which said latch rod extends,

spring means engaging said body and latch rod to resiliently hold theassembly in predetermined position, a peripheral groove on the latchrod, and latch means urged inwardly against the latch rod by said lastmentioned means to engage and releasably latch the assembly in positionwhen one of the valve members engages its associated valve seat.

7. A iiow valve comprising a valve body having a passageway with aninlet and an outlet, a valve assembly movable axially of the passageway,said assembly including a tubular member having oppositely extendingvalve members, opposed valve seats adapted to be engaged by saidmembers, means normally urging the assembly to a position to close theinlet, and an annular piston surrounding said tubular member andsealably engaging the walls of the passageway so that the valve assemblymoves within the passageway in accordance with the differential pressureat the inlet and outlet.

8. A ow valve comprising a body having a passageway, opposed valve seatstherein, a valve assembly movable within the passageway and includingvalve members adapted to engage said seats, a chamber in alignment withthe passageway, a rod attached to the valve assembly and extending intosaid chamber, a piston on the rod, a liquid within the chamber, springmeans within the chamber urging the piston assembly to a. predeterminedposition, a restricted bypass about the piston whereby movement of thevalve assembly is retarded, and a latch means within said chamber toreleasably latch the valve assembly in position to close the passageway.

9. A flow valve comprising a valve body having a passageway with spacedinlet and outlet openings, spaced opposed metering chambers in saidpassageway, each of said chambers having a valve seat at its innermostend, said inlet opening communicating with one of said chambers, .and a`valve member movable axially of said passageway, an annular pistonsurrounding said valve member intermediate its ends, said member havingoppositely extending valve seating surfaces adapted respectively toengage one of said valve seats, there being a passage through the valvem'ember from the inlet side of the piston and terminating in the seatingsurface at the opposite end of the member.

10. A valve assembly comprising a valve member having ends of reduceddiameter terminating ln converging seating surfaces to cooperateconverging metering walls and end seats in a valve chamber so that flowof fluid pressure through such chamber is metered, a latch rod securedto said assembly, a latch cooperable with said rod,

and a spring adapted to urge said assembly to its closed position at oneend of its travel and to impart force to said latch.

11. A valve assembly comprising a valve member having ends of reduceddiameterterminating in converging seating surfaces to cooperateconverging metering walls and end seats in a valve chamber so that flowof fluid pressure through such chamber is metered, a latch rod securedto said assembly, a latch cooperable with said rod, a spring adapted tourge said assembly to its closed position at each end of its travel andto impart force to said latch, and a lubricant within the chamber aboutsaid spring and latch.

12. A valve assembly comprising a valve member having ends of reduceddiameter terminating in converging seating surfaces to cooperateconverging metering walls and end seats in a valve chamber so that flowof fluid pressure through such chamber is metered, a latch rod securedto said assembly, a latch cooperable with said rod, a spring adapted tourge said assembly to its closed position at each end of its travel, andto impart force to said latch, and a viscous lubricant within thechamber about said latch whereby the movements of said valve assemblyare controlled against the action of false differentials in saidchamber.

13. A flow valve having a valve body and a shell, a valve assemblyslidable axially in said shell, means on said valve assembly and in saidshell for metering pressure fluid, an extension on said valve assemblyengageable with a spring to normally urge said valve assembly to itsextreme intaking position, latching means operable by said spring toresiliently urge said valve assembly to resist movement away from eachof its extreme positions, and a viscous lubricant to delay all movementsof said valve assembly.

14. A flow valve having a valve body and a shell, a valve seat memberpositioned in said `shell so as to divide the interior of said shellinto two chambers, a valve assembly having a passage therethrough forpressure uid in one of said chambers, latching means in the other ofsaid chambers, said means being adapted to resiliently urge said valveassembly to resist movement thereof from its extreme closed positions, aviscous lubricant in said other chamber to retard all movements of saidvalve assembly, a metering chamber at each end of said first chamberadapted to coact with the ends of said valve assembly in meteringpressure fluid, and a valve seat in each of said metering chambersengageable by said asproximately true differentials.

16. A metering valve assembly in combination with latching means and aviscous lubricant for causing said valve assembly to resist the force offalse dilferentials acting upon said assembly, comprising a pistonhaving a valve on each end thereof, said assembly and valves having anaxial passage therethrough and al lateral opening through one of saidvalves, said opening communicating with said passage, said latchingmeans comprising an extension secured to said valve assembly, a latchfloor and a latch roof, latch balls contactlng said extension, iloor androof, and a spring adapted to coact with said floor to cause said ballsto resiliently engage within recesses formed around said rod, and saidviscous fluid contained within a chamber of said shell to lubricate saidlatch and resist the force of false dilerentials acting upon said valveassembly.

' ALEXANDER BOYNTON.

